The confinement layers in the present case are material layers or sequences of material layers that are capable of confining charge carriers to a photon-generating active region of the layer structure.
In the present context, the term “confinement layer” encompasses both a single material layer and a sequence of material layers that comprises the function of a confinement layer. Analogously, the term “photon-emitting layer” encompasses both a single material layer and a sequence of material layers that is capable of emitting photons when operating.
The present patent application claims the priority of the German patent application having the application number 103 29 079.6 (priority date: Jun. 27, 2003), whose disclosure content is hereby incorporated into this application by reference.
In laser diodes and light-emitting diodes (LEDs) based on AlInGaP, but also on other material systems, efforts are made to obtain the highest possible n-doping in the confinement layers in order to minimize charge carrier losses due to leakage currents. At the same time, a sharp drop-off in doping at the edge of the waveguide of a laser diode is desirable to prevent increased absorption of the laser mode. If these conditions are met, however, the electrical, optical and/or electro-optical quality of the active layer (whether doped with the n-dopant or not) is frequently unsatisfactory. On the other hand, the use of other dopants that improve the electrical or optical quality of the active layer leads to other disadvantages, such as lower efficiency for the components produced.